1. Field of the Invention
The present invention relates to a golf address deviation detecting apparatus for detecting inaccuracies in loft angle, lie angle, and face orientation upon address by a golf club.
2. Description of Related Art
FIG. 45 through FIG. 53 show the related art. There are typically known a loft angle, a lie angle, and a face orientation as factors for analyzing address by a golf club. As shown in FIG. 45, the “loft angle” is an angle defined between a face and an uprighted shaft of a golf putter as a golf club when viewed from a lateral or near side of the golf club, upon address by the golf club. Further, as shown in FIG. 46, the “lie angle” is an angle defined between the shaft and a ground surface when viewed from a front side of the golf putter upon address by the golf club.
There will be explained inaccuracies in loft angle, lie angle, and face orientation. For example, in case of putting on a green, there is determined an ideal address upon putting so that ideal loft angle, lie angle, and face orientation are also determined, depending on conditions upon putting, such as an undulation of the green, a grain direction and a hardness of a turf, a distance from a putting location to a hole, and a body type and an address-form of a golfer.
The “inaccuracy in loft angle” refers to a difference between an actual loft angle by a golf form and an ideal loft angle. Further, the “inaccuracy in lie angle” refers to a difference between an actual lie angle by the golf form and an ideal loft angle. Furthermore, the “inaccuracy in face orientation” refers to a difference between an actual face orientation by the golf form and an ideal face orientation.
In turn, inaccuracies in loft angle, lie angle, and/or face orientation are caused in: a situation where selection of a golf club is incorrect; a situation where selection of a golf club is correct, but inaccuracy is caused in a golf form, thereby resultingly and possibly causing inaccuracies in loft angle, lie angle, and/or face orientation; and/or the like situations.
There will be now explained a problem in case of occurrence of inaccuracy in face orientation. FIG. 47(b) shows a situation where a face orientation is accurate. FIG. 47(a) and FIG. 47(c) show situations where inaccuracies are caused in face orientations, respectively. Although the face orientation is directed toward a hole in case of accuracy shown in FIG. 47(b), face orientations are not directed toward the hole so that face orientations are wrong in case of inaccuracies shown in FIG. 47(a) and FIG. 47(c).
There will be next explained a problem in case of occurrence of inaccuracy in loft angle. FIG. 48(b) shows a situation where a loft angle is 0 (zero) degree. FIG. 48(a) shows a situation of a typical loft angle. FIG. 48(c) shows a situation of a large loft angle. In this way, different loft angles lead to different hitting directions of balls, respectively, such that inaccuracies in loft angle largely affect putting distances in golf.
There will be now explained a problem in case of occurrence of inaccuracy in lie angle. In case of occurrence of inaccuracy in lie angle, such an inaccuracy is problematically actualized into inaccuracies in face orientation and loft angle.
Firstly, there will be explained a reason why inaccuracy in lie angle is actualized into inaccuracy in face orientation. FIG. 49(a) shows a state of a face viewed from a front side thereof, upon putting a ball. FIG. 49(a) shows a face in an accurate state by a solid line, and a face in a heel-up state by a dotted line. FIG. 49(b) shows inclinations of cutting intersections between the faces and a horizontal plane S shown in FIG. 49(a), in a manner viewed from the above. FIG. 49(b) shows the cutting intersection of the face in the accurate state by a solid line. Further, FIG. 49(b) shows the cutting intersection of the face in the heel-up state by a dotted line. As shown in FIG. 49(b), the cutting intersection of the face in the heel-up state is inclined, with respect to the cutting intersection of the face in the accurate state. This leads to such a phenomenon that although a ball putted by the face in the accurate state is allowed to roll in a direction (represented by a solid line in the figure) toward a hole, a ball putted by the face in the heel-up state is rolled in a direction (represented by a dotted line in the figure) deviated from the hole direction. Namely, occurrence of inaccuracy in lie angle problematically leads to occurrence of inaccuracy in face orientation.
Next, there will be explained a reason why inaccuracy in lie angle is actualized into inaccuracy in loft angle, based on FIG. 50. FIG. 50(a) shows a state of a face viewed from a front side thereof, upon putting a ball. FIG. 50(a) shows a face in an accurate state by a solid line, and a face in a heel-up state by a dotted line. FIG. 50(b) shows inclinations of cutting intersections between the faces and a vertical plane T shown in FIG. 50(a), in a manner viewed from a lateral side (arrowed direction). FIG. 50(b) shows the inclination of the face in the accurate state by a solid line. Further, FIG. 50(b) shows the inclination of the face in the heel-up state by a dotted line. As shown in FIG. 50(b), the cutting intersection of the face in the heel-up state is inclined, with respect to the cutting intersection of the face in the accurate state. This leads to such a phenomenon that although a ball putted by the face in the accurate state is allowed to roll after passing through a direction represented by a solid line in the figure, a ball putted by the face in the heel-up state is rolled after passing through a direction represented by a dotted line in the figure. Namely, occurrence of inaccuracy in lie angle problematically leads to occurrence of inaccuracy in loft angle.
On the other hand, inaccuracies in loft angle, lie angle, and face orientation upon address by golf club may be caused by incorrect selection of the golf club.
As explained above, inaccuracies in loft angle, lie angle, and face orientation may be each independently caused or may be caused in a mutually affected manner. It has been thus difficult to detect as to which of inaccuracies in loft angle, lie angle, and face orientation, inaccuracy in a ball-hitting direction is caused by. As such, it has been difficult to appropriately correct a golf form and to select a golf club suitable for a golfer.
In this respect, JP-A-2002-159606 has disclosed an invention related to a putting practice tool for detecting inaccuracies in a golf form.
The putting practice tool is configured to include a double-faced adhesive tape pasted to a reverse surface of a reflection plate, and the reflection plate is stuck on a face of a putter, such that laser light irradiated from a laser light source is reflected by the reflection plate and then projected onto a projection plate.
According to JP-A-2002-159606, upon occurrence of inaccuracies in a golf form, it is certainly possible to detect such inaccuracies based on a position of reflectedly projected light on the projection plate, which position is deviated from an accurate position of the reflectedly projected light. However, it is impossible to conduct the detection to such an extent to detect as to which of inaccuracies in loft angle, lie angle, and face orientation the inaccuracies in the golf form are caused by. In this way, inaccuracies in the golf form have not been specified, thereby problematically making it difficult to correct the golf form.
In this concern, it is possible to provide a face of a golf club with a light emitting unit so as to project light irradiated from the light emitting unit onto a light receiving area, thereby detecting deviations in golf address based on a position of the projected light on the light receiving area. However, similarly to JP-A-2002-159606, although it is then certainly possible to detect inaccuracies in a golf form, it is impossible to conduct the detection to such an extent to clearly detect as to which of inaccuracies in loft angle, lie angle, and face orientation the inaccuracies in the golf form are caused by.
Further, FIG. 51 through FIG. 53 schematically show a golf address deviation detecting apparatus, which has been already practiced. The apparatus is configured to include an apparatus body 102 provided with a light irradiating unit 101, and a light reflection plate 103 provided at a face of a putter 104 so as to reflect point-shaped laser light irradiated from the light irradiating unit 101, in a manner to project the laser light reflected by the light reflection plate 103 onto a light receiving area 105.
The apparatus is intended to detect inaccuracies in a golf form based on the position of the light projected onto the light receiving area 105, as described later.
FIG. 53 shows positions of projected light in situations where a loft angle, a lie angle, and a face orientation are accurate, and situations where inaccuracies are caused in them. In FIG. 53, black dots represent positions of projected light, respectively.
However, in FIG. 53 concerning the related art, even by comparing the situations of accuracy and inaccuracies in lie angle with the situations of accuracy and inaccuracies in face orientation, the positions of the projected light in case of occurrence of inaccuracies in lie angle are the same as the positions of the projected light in case of occurrence of inaccuracies in face orientation as apparent from FIG. 53, so that both cases can not distinguished from each other.
Such a phenomenon is caused by the fact that inaccuracies in lie angle are actualized into inaccuracies in face orientation, as described above.